The osmotic pressure of the media used for in vitro swelling evaluation has been shown to have a significant effect on material swelling behavior. In this study, the effect of osmotic pressure during swelling in vitro on poly(vinyl alcohol) (PVA) hydrogel material properties was evaluated. Osmotic pressure solutions are necessary in order to mimic the swelling pressure observed in vivo for soft tissues present in load-bearing joints. Hydrogels were characterized after swelling by mechanical testing, x-ray diffraction, and optical microscopy in the hydrated state. Results indicated hydrogel mechanical properties remained tailorable with respect to initial processing parameters; however, significant aging occurred in osmotic solution. This was observed when evaluating mechanical properties, where before swelling hydrogels ranged from 0.04 to 0.78 MPa and after swelling in vitro using osmotic pressure solution hydrogels ranged between 0.32 to 0.93 MPa. Significant aging was also noted when evaluating crystallinity, where relative crystallinity was seen to range between 0.4 to 5.0% before swelling and between 6.5 to 8.0% after swelling. When compared to swelling in non-osmotic pressure solution, or phosphate buffered saline solution, mechanical properties were more dependent upon final swelling content. Furthermore, increases in crystallinity were not as significant after swelling. These results display the importance of choosing the appropriate swelling medium for in vitro characterization based on the desired application.